Question about Dell UltraSharp U3219Q

No problems for me. And that's not normal either. You certainly still have a guarantee. You should use it.

I have the same monitor and I haven't noticed this yet. However, I have been using it for even less time.
I would definitely file this as a warranty claim, as this behaviour simply should not happen with the Ultrasharp series.
I previously had the U3011 in almost daily use at work for over 9 years and never had this problem. (I only changed because of the higher resolution of the U3219Q).

Mine doesn't do that. So it is probably broken.